CHINO HILLS - Southern California Edison indicated on Tuesday that placing new high voltage power lines underground, instead of above ground through Chino Hills, would mean abandoning $16 million already spent on construction costs, and an additional $2 million to remove towers that have already been constructed in the past year.

Total estimated costs for each of the five proposed underground transmission configurations for the Chino Hills segment of the Tehachapi Renewable Transmission Project range from about $486 million to $807 million, according to an Edison document. The costs are preliminary and subject to change, but they're considerably higher than the original $172 million cost for constructing the above-ground transmission line segment through Chino Hills.

The statement is part of testimony ordered by the California Public Utility Commission to investigate alternatives to the line after the city of Chino Hills filed a petition against the above ground project last year. The commission deadline for the commission to receive the testimony is today. The commission is expected to make a decision on whether to underground the transmission lines on July 11, 2013.

Despite Edison having started construction work on towers for the Chino Hills segment of the Tehachapi Renewable Transmission Project, the California Public Utilities Commission voted last year to require the power company to submit testimony regarding the cost of under-grounding the lines.

The city and some residents have called for an alternate route around the city, or underground along the easement, citing concerns over aesthetic degradation, decreased home values and safety.